Safe Mobility at Any Age Identifiers of High-Risk Drivers:

An Occupational Therapy Perspective

Wendy Stav, PhD, OTR/L, CDRS

University of Florida

National Older Driver Research & Training Center

Topic Areas

• Assessment options

• What the government wants

– Florida Programs

• The realities of safety thresholds

• The National Older Driver Research and

Training Center

Assessment Options

• Consider what should be assessed

– Vision

– Cognition

– Motor Performance

– Reaction Time

– Roadway knowledge

• Are older drivers different from

rehabilitative clients?

• What level assessment is being done?

Assessment of Vision

• Snellen Chart

• OPTEC series

• Keystone Vision Tester

• Perimetry Testing

• Visual Perception Tests

OPTEC

• Interchangeable slides

– Static Acuity

– Peripheral Fields

– Depth Perception

– Color Discrimination

– Phorias

– Road Signs

– Contrast Sensitivity

• 3000 version- glare

recovery

Perimetry Testing

• Useful in identifying

blind spots/field cuts

• Gross deficits

obvious

• Unknown effect of

mild deficit on driving

• Need referral to eye

care practitioner

Porto-Clinic / Glare

• Tests:

– Visual Activity

– Field Of Vision

– Depth Perception

– Color Perception

– Simple Reaction

– Complex Reaction

Response

– Glare Recovery

– Night Vision

Contrast Sensitivity

Visual Perceptual Tests

• MVPT – 3

• TVPS

• TVMS

• Bender – Gestalt

• Block Design

Cognitive Assessment Tools

• Trails A and B

• ACLS Leather Lacing

• Digit Symbol

• Stroop

• UFOV

• Map Skills

• Problem solving scenarios

Trailmaking A & B

• Paper pencil test

• Quick and easy to administer

• Trails A – connect numbers

sequentially

• Trails B – connect numbers/letters

alternatively and sequentially

• Assesses:

Attention Problem solving

Scanning Divided attention

Planning Attention shift

Trails B

Allen Cognitive Level Screen

• Leather lacing

• Quick / easy to administer

• Level 5.6 to drive safely

• Poor face validity

Stroop

• Neuropsychological

Screen

• Paper test

• Quick to administer

• Assesses

– selective attention

– mental flexibility

BLUE GREEN

GREEN BLUE

RED RED

TAN BLUE

GREEN TAN

BLUE RED

Useful Field of View

• Visual Processing Speed

• Divided Attention

• Selective Attention

• Per test fee

• Psych Corp

• Visual Awareness, Inc.

Block Design

• Identifies issues with:

– Planning

– Organization

– Problem solving

– Frustration

Symbol Digit

Motor / Sensory Assessments

• Functional Quick Screen

• Manual Muscle Testing

• Dynamometer

• Diadochokokinesis

• Posture/Stature assessment

• Proprioception / Kinesthesia

Reaction Time

• Combination of:

– Sensory awareness

– Cognitive processing

– Execution of a motor

response

Assessment of Driver-Vehicle Fit

• Ergonomic Perspective

• Small drivers in large vehicles

• Prevent injury through:

– Proper positioning

– Appropriate use of vehicle safety features

• Address positioning with regard to:

– Seat

– Seat belt

– Mirrors

– Air bag

– Foot pedals

Driver – Vehicle Fit Guidelines

• Sit 10-12” from airbag

• Angle steering wheel at chest

• Eyes at least 3” above steering wheel

• Access to foot pedals

• Mirrors positioned to allow greatest visual access to environment

• Head rest positioned no lower than ear level

• Seat belt- shoulder belt crossing middle of clavicle

• Seat belt- lap belt low across hips on ASIS on pelvis

Clinic testing will NOT produce definitive answer whether a person can drive safely or

not!!

Clinic testing WILL provide a picture

of how the client will likely perform in

the vehicle.

Safe Not Safe

What the Government Wants

• Federal and State governmental agencies

• Looking for a “silver bullet”

• Assessment that identifies high risk drivers

– Inexpensive

– Fast

– Reliable

– High Sensitivity

– High Specificity

– Non-Biased

– Politically acceptable

Government’s Unrealistic Expectations

• Inexpensive

– Validated tools cost money to develop/ test

• Fast

– Too fast and things are missed

• Reliable

– Inexpensive to administer = non-professionals

• High Sensitivity and Specificity

– Does not yet exist

• Non-Biased

– A possibility in a perfectly homogonous society

• Politically Acceptable

– An oxymoron in older driver testing

Florida’s Programs • Florida Aging Driver Council

• Florida At-Risk Driver Council

• Florida Senior Safety Resource Centers

• Tiered Assessment Model

– Screening – Community level

• DriveABLE, UFOV, GRIMPS

– Assessment – DMV / physician

• AMA screen

– Evaluation – Occupational Therapist / DRS

• Comprehensive clinic based and behind-the-wheel

Florida Senior Safety

Resource Centers

• Website

• http://fssrc.phhp.ufl.edu/index.php

• Self Assessment

• Transportation resources

– Listed by county

– Name, eligibility, cost

• Links

The Realities of Safety Thresholds

• Study conducted as part of the Elder

Mobility Project

• South Florida – elder dense area

• Funded by FL Dept of Transportation

• Comprehensive program

– Education

– Assessment & feedback

– Counseling & Mobility Management

The Clients

• 323 Well elderly drivers from South Florida

• Voluntary program

• Most self-referred

• 74% participated after reading newspaper

• 6% referred

– Physicians

– Traffic court judges

– Law enforcement

– Local Memory Disorder Centers

Referral Source of Clients

newspaper

family

friend

physician

court

law enforcement

radio

television

55 Alive

presentation

other

agency

unknown

74%

Data

• Results from all

assessments collected

• Only certain tools had

established safety

thresholds

• Performance on those

tools compared to safety

thresholds

Tools with Thresholds

Trialmaking B

2m 30s (Staplin,1999)

2m (Raleigh, 2000)

Tools with Thresholds

Useful Field of View

Category 4 or 5

(Ball, Owsley, Sloane,

Roenker, Bruni, 1993)

Tools with Thresholds

AAA Brake

Reaction Timer

Slower than .5

seconds

Tools with Thresholds

Stroop

Neuropsychologic

al Screen

>2 minutes

(Trenerry, Crosson,

DeBoe, Leber, 1989)

BLUE GREEN

GREEN BLUE

RED RED

TAN BLUE

GREEN TAN

BLUE RED

Analysis

• Data analyzed with descriptive statistics

• Compared to industry accepted safety thresholds

• Secondary analysis

– Correlation of assessment results with age

– Pearson product-moment coefficient for interval data

– Spearman’s Rho correlation coefficient for ordinal data

Trails B Distribution for Older Adults

0

5

10

15

20

25

30

35

40

Time for Completion

Nu

mb

er

of

Cli

en

ts

2:00 Cut-Off 40% of Clients

Mean = 2:15 (SD 1:41)

2:30 Cut-Off 23% of Clients

Cat 5

Cat 4

UFOV Category Ratings of Older Drivers

Cat 1

Cat 2 Cat 3

20.2% are

High Risk

Stroop Performance of Older Drivers

Mean 3:00 SD (1:17)

0

10

20

30

40

50

60

Time for Completion

Nu

mb

er

of

Cli

en

ts

Mean = 3.01 (SD 1.17)

>2:00 Impaired Cognition (82.4%)

< .5 sec > .5 sec

Brake Reaction Timer

53% “Safe”

47% “Unsafe”

Age Correlations

Tool Age

Coeff.

Trailmaking B .196

Stroop .186

Brake Rx Timer .030

UFOV .408*

*.01 Significance level

Safety Thresholds • Set by establishing predictability of crashes

• Typically prospective studies

• The problem: crashes are rare occurrences

• Driving is human performance

• Need to study the predictability of driving

performance

Conclusion

• Age is not necessarily related to

decreased performance

• Significant discrepancies between

“normal” and safe performance

• Well elderly may be high risk drivers

• Current assessments / thresholds are

problematic

More Questions

• Are older driver stereotypes correct?

• Have we identified the wrong assessments?

• Are the tools valid to assess driving?

• Are the tools sensitive enough, or too sensitive?

• Are these large segments of the older population

really at risk?

• Do we need a paradigm shift from crash risk to

driving performance?

National Older Driver

Research and Training Center

• University of Florida

• Funded by

– Center for Disease Control

– Federal Highway Administration

• Multidisciplinary team

– 10 team members (OT, computer engineering,

public health, transportation safety)

– 9 support staff (grant writers, budget preparers,

computer support, administrative support)

NODRTC

• International Consensus Conference (12/03)

– Assessment Panel

– Remediation Panel

– Alternate Transportation Panel

• Reports from committees shaping future

NODRTC

• Federal Highway Administration

– Older driver performance and

problematic roadway conditions

– Instrumentation of vehicles for objective

performance measures

– Replication with Driving Simulator

NODRTC

• Centers for Disease Control

– Development of comprehensive program

offering assessment, remediation, and

counseling

– Subcontract with AOTA to increase the

capacity of OTs to work with older drivers

NODRTC

• Setting up 4 data collection sites in Florida

• Examine use of vehicle safety features

• Evaluate the impact of medications on driving

performance

• Identify assessment tools predictive of driving

performance

• Evaluate the most effective methods of driver

training

Questions